body h2{
    text-decoration: none;
}
#nav{
    width: 300px;
    background: darkgrey;
}
#nav:hover{
    background: white;
}
.title{
    font-size: 18px;
    font-weight: bold;
    text-indent: 1em;
    line-height: 35px;
    background: red;
}

ul li{
    height: 30px;
    /*
    none：去除列表前缀，圆点/数字序号
    circle：空心圆
    decimal：数字
    square：正方形
    */
    list-style: none;
    text-indent: 1em;
}
a{
    text-decoration: none;
    font-size: 14px;
    color: black;
}
a:hover{
    color: blue;
    text-decoration: underline;
}